Help 86 300E ignition problem

[jmyers177]

Ignition begins to fail after 5 to 10 minutes of running but it isn't a total failure. It will idle fine but when you try to load the engine or try accelerate it will die. Testing so far is as follows. We have determined that the temp sensor is working correctly, the throttle position switch is working and the vacuum line ti ig module is connected. We have tried putting a timing light on and watching it when the problem occurs and it goes completely dark or not firing when you advance the throttle suddenly. If you advance the throttle very slow with no load the engine will rev up and run fine at higher RPM's. We tried the timing light on both the coil and #1 to make sure it was not a problem with the coil. The firing stops on the coil lead before the distributer to rule out some problem with the dist. The ignition module is not getting hot nor is the coil. Without expensive diagnostic equipment we are stumped or at least led to believe the ignition module is bad.
One other problem is that once it fails, you can't get it started until it is left for several hours. When trying to start, it appears to be firing, but erratic. The timing light indicates it is firing but the engine belches, kicks back, etc like it is firing out of sequence. I would have suspected the hall effect sender but it runs so well at higher RPM's it should be okay. It (the crank position sensor) measures about 780 ohms.

Any help really appreciated.

John